Optical information recording and reproducing apparatus

Abstract

Provided is an optical information recording and reproducing apparatus for recording and reproducing information using holography by irradiating a spatial modulator with a light beam from a first laser light source, separately generating information light and reference light sharing an optical axis, and condensing the generated light beam onto the information recording medium by an objective lens including a driving unit for moving the objective lens, in which the driving unit moves the objective lens in parallel to the light beam in accordance with the incident angle of light passing through the center of the spatially modulated light beam with respect to the information recording medium. The apparatus enables a stable recording and reproduction performance operation even in the case where a relative tilt occurs between an information recording medium and an optical pickup without enlarging an apparatus.

1 . An optical information recording and reproducing apparatus, comprising: 
 a first laser light source;    a spatial light modulator for generating information light and reference light sharing an optical axis from a light beam of the first laser light source;    an objective lens for irradiating an information recording medium with a light beam from the spatial light modulator; and    a driving mechanism for moving the objective lens in a direction orthogonal to an optical axis of the objective lens in accordance with an incident angle of light passing through a center of the spatially modulated light beam with respect to the information recording medium.    
   
   
       2 . The optical information recording and reproducing apparatus according to  claim 1 , further comprising: 
 a second laser light source for emitting laser light to the information recording medium which is non-photosensitive thereto; and    a photodetector for detecting a light beam irradiated from the second laser light source and reflected by the information recording medium,    wherein the incident angle is detected by the photodetector.    
   
   
       3 . The optical information recording and reproducing apparatus according to  claim 2 , wherein the driving mechanism integrally drives the spatial light modulator, the objective lens, the second laser light source, and the photodetector in accordance with the incident angle.